javascript: void((() => {
  /**
   * 放大百度知道中点开的预览图 v2
   * g8up
   * 2020年4月4日
   */
  const getTransformVal = (el, prop) => {
    return el.dataset[prop];
  };

  const getRotateZ = el => (getTransformVal(el, 'rotateZ') || 0);
  const getScale = el => (getTransformVal(el, 'scale') || 1);

  const setTransform = (el, props) => {
    const {
      rotateZ = getRotateZ(el),
        scale = getScale(el),
    } = props;

    el.style.transform = `scale(${scale}) rotateZ(${rotateZ}deg)`;
    Object.assign(el.dataset, {
      rotateZ,
      scale,
    });
  };

  const img = document.querySelector("body > div.q-img-fullscreen-wraper > img");
  if (img) {
    let init = +getScale(img);

    img.onmousewheel = (e) => {
      e.preventDefault();
      const isDown = e.wheelDelta < 0;
      setTransform(img, {
        scale: isDown ? init -= 0.1 : init += 0.1,
      });
    }
  } else {
    console.log(`未找到点开的缩略图。`);
  }
})());